Journal of Applied and Natural Science

10 (2): 779 - 790 (2018)

ISSN : 0974-9411 (Print), 2231-5209 (Online)

journals.ansfoundation.org

Integrated weed management in direct seeded rice in Trans Indo-Gangetic plains of India- A review

Ajay Singh* Department of Agronomy, CCS Haryana Agricultural University, Hisar-125004 (Haryana), India

D. P. Nandal Department of Agronomy, CCS Haryana Agricultural University, Hisar-125004 (Haryana), India

S. S. Punia Department of Agronomy, CCS Haryana Agricultural University, Hisar-125004 (Haryana), India

Priti Malik Department of Agronomy, CCS Haryana Agricultural University, Hisar-125004 (Haryana), India

*Corresponding author. E-mail: ajayyadavhau@gmail.com

Abstract In the Indo-Gangetic Plains (IGP) of India, rice (Oryza sativa L.) is taken by conventional tilled puddled transplanted (CT-PTR) method. CT-PTR requires a lot of water (2000-2500 mm) which comes mainly from groundwater. Due to declining water table and changing climate, the sustainability of CT-PTR rice is under immense pressure. The alternative to CT-PTR could be direct seeded rice (DSR) which requires less water, labor, initial cost and energy than CT-PTR. But direct seeded rice is heavily infested with weeds which cause severe loss to the grain yield. Thus, the success of aerobic rice depends on effec-tive and timely weed control. As a single weed control method may not be successful on a long term basis, weed problem in direct seeded rice needs to be solved by integrated approach. Integrating cultural, mechanical and chemical methods along with highly com-petitive cultivars with effective allelopathic properties, effective weed management on long term sustainable basis can be achieved.

Keywords: Aerobic rice, Allelopathy, Competitive Cultivars, Direct seeded rice, Pud-

dled transplanted rice

Article Info

DOI:10.31018/jans.v10i2.1679 Received: February 24, 2018 Revised: April 25, 2018 Accepted: May 18, 2018

How to Cite Singh, A. et al. (2018). Integrated weed manage-ment in direct seeded rice in Trans Indo-Gangetic plains of India- A review. Journal of Applied and Natural Science, 10(2): 779 - 790

INTRODUCTION

Rice (Oryza sativa L.) is the most important cereal crop of India and feeds the belly of more than 800 million Indians. It has a share of 41.39% in total food grain produced and 55% of cereals produced in the country, contributing 20-25 % to Agricultural GDP (Anonymous, 2016). In India, rice is grown on nearly 43.49 m ha with total production of 104.4 m t and productivity of 2400 kg/ha (Anonymous, 2016). In India, the IGP cover about 20% of the total geo-graphical area (329 Mha) and about 27% of the net cultivated area, and produce about 50% of the total food consumed in the country (Dhillon et al., 2010). It is spread across five Indian states, Pun-jab, Haryana, Utter Pradesh, Bihar and West Ben-gal. Trans Indo Gangetic Plain (TIGP) in India is spread across Punjab and Haryana. TIGP consti-tute a highly productive RW zone contributing about 69% of the total food output i-n the country (about 84% wheat and 54% rice) and this region is called the “food bowl of India.” This region has played a vital role in sustaining the food security of India by contributing about 40% of wheat and 30% of rice to the central stock of India every year dur-

ing the last four decades (Hira and Khera, 2000). In the Indian perspective, a target production of 130 MT (Million tonne) of rice has to be achieved by 2020-2021, which means 5-6% increase in total production annually, to feed ever increasing population. The possibility of increase in area in the near future is very limited mainly due to fast urbanization, utilization of productive land for non-agricultural purposes and land degradation. Therefore, the extra rice needed must come from gain in productivity. The main hindrance in achiev-ing this target are: (1) inefficient use of inputs (fertilizer, water, labour); (2) less availability of water and labour; (3) climate change; (4) the emerging crisis of energy and rising fuel prices; (5) the rising cost of cultivation; and (6) other problems like rapid urbanization, labbour migra-tion to cities (Ladha et al., 2009). In India, mainly puddled transplanted rice is taken. In transplanted rice, first rice nursery is raised and thereafter 20-30 days old seedlings are transplant-ed into puddles soil. Puddling makes an impervi-ous layer which reduces percolation loss, creates anaerobic conditions to increase availability of nutrients and suppresses weeds (Bhurer et al.,

This work is licensed under Attribution-Non Commercial 4.0 International (CC BY-NC 4.0). © 2018: Author (s). Publishing rights @ ANSF.

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2013). But repeated puddling destroys soil aggregates, thereby decreasing permeability in sub-surface layers and forming hard-pans (Aggarwal et al., 1995; Sharma and Datta, 1985; Sharma et al.,2003), all of these prove detrimental to suc-ceeding crop usually wheat in IGP (Hobbs and Gupta, 2000). Moreover, puddling requires additional water (~200 mm) which is becoming scarce day by day and labour which becoming costlier each day. So, with increasing cost of cultivation paddy produc-tion is become less profitable to the farmers. In India per capita water availability decreased by 72.3 % between 1951 and 2005 (5831 m3and 1611 m3 in 1951 and 2015 respectively) and is likely to decline by 77.8 % by 2050 (1292 m3 in 2050). So scarcity of water, less availability of la-bour acts as driving force for direct seeding (Kumar and Ladha, 2011). All these above factors demand a major shift from conventionally tilled- puddle transplanted rice (CT-TPR) to direct seed-ing of rice (DSR). Pandey and Velasco (2002) argued that trans-planted is prevalent in areas where wages rates are low and water availability is enough whereas high wage rates and less availability of water fa-vours adoption of direct seeded rice. So, aerobic rice could replace puddled transplanted rice. Di-rect seeded rice matures 7-11 days earlier than transplanted rice allowing timely sowing of next crop (Giri, 1998; Singh et al., 2006). Other benefits of DSR include easier planting by direct seeded machine, improvement of soil struc-ture, higher tolerance to water deficit, less emis-sion of methane and often higher profit in areas with an assured water supply (Datta, 1986). Both Dry and Wet-DSR have the potential to reduce the water and labour use compared with CT-TPR. Tabbal et al. (2002) under on-farm trials in Philip-pines observed on an average 67-104 mm of sav-ing in irrigation water in Wet-DSR compared with puddled-transplanted rice when irrigation applica-tion criteria was same for both establishment methods. Other than saving water, DSR reduced total labour requirement 11%-66% depending on season, location and type of DSR compared with CT-TPR (Kumar et al., 2009; Rashid et al., 2009). Labour requirements for crop establishment de-creased by more than 75% with direct seeding compared with transplanting (Dawe, 2005; Pan-dey and Velasco, 2002). But direct seeded rice are heavily infested with weeds, so success of DSR depends on effective weed management (Chauhan and Yadav 2013; Singh et al., 2006a; Rao et al., 2007; Singh et al., 2007). Many studies have reported the potential for DSR as a replacement for transplanted rice if weeds are controlled effectively (Singh et al., 2007). Aerobic systems are subjected to much

higher weed pressure than CPTR (Rao et al., 2007) in which weeds are suppressed due to pre-vailing anaerobic environment in flooded condi-tions and by 25-30 days old transplanted seed-lings which have an edge over germinating weed seedlings(Moody, 1983). So managing weeds effectively is the major chal-lenge in DSR, as failure to manage weeds results in very low or no yield (Singh et al., 2008; Moody and Mukhopadhyay, 1982). In DSR first 30-45 days after sowing is critical period and weeds must be managed effectively in this period other-wise there will be much loss in the yield. Maity and Mukherjee (2008) reported that uncontrolled weeds reduced the yield by 96% in dry-DSR and 61% in wet-DSR. So the success of DSR depends largely on effec-tive weed management especially the integrated approach. As a single method may not provide adequate control and for long term sustainability, integrated approach is the best option. Weed flora of DSR: Direct seeded rice is infested by complex weed flora including various grasses, broadleaf and sedges. Singh et al. (2017) reported Echinochloa glabrescens, Leptochloa chinensis, Cyperus spp. Ammania baccifera, Eclipta alba as predominant weed species in direct seeded rice at Kaul (Kaithal) Haryana. Saha (2006) reported that DSR was mainly infested by sedges including Cyperus difformis (30.2%), Fimbristylis miliacea (27%) followed by BLW Ludwigia parviflora (17.5%) Sphenochlea zeylancia (15.8%) and grasses Echinochloa colona (9.5%). However, Mishra and Singh (2008) reported that direct seeded rice was infested mainly by BLW including Phyllanthus spp.(26.5%), Commelina communis (17.8), Physlis minima (1.8%), Alter-nanthera sessilis (5.9%), Caesulia axillaris(1.2%), grasses Echinochloa colona (31.8%) and sedges Cyperus iria (9.9%). So the composition and spe-cies of weed vary from region to region. Losses caused by weeds: The productivity of crops to a greater extent depends upon efficient resource management. Among many factors re-sponsible for low yield in Indian agriculture, prob-lem of weed is one of the major factors causing losses in crop yield in general and under direct seeded rice in particular. Heavy weed infestation and poor weed management contribute to poor yield in aerobic rice (Bhurer et al., 2013). Crop-weeds competition depends on a number of factors such as the weed species, type of rice cul-ture, methods of planting and cultural practices. Rice crop suffers more if weeds compete for re-sources during initial crop growth period and com-petes for a longer period. This results in poor growth of rice plants which eventually leads to poor yield. Weeds heavily repress the growth of rice during initial 30-40 days. The slow initial seedling establishment and growth

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of young seedlings are more sensitive to weed competition in direct seeded rice and yield loss up to 57.6 % due to uncontrolled weed growth has been reported by Singh (2017). Aerobic conditions along with alternate wetting and drying favours the germination and growth of weeds in direct seeding which causes yield loss upto 50-91% (Bhurer et al ., 2013; Singh and Chinnusamy, 2006). Bhurer et al. (2013) claimed that weeds are sup-posed to be the foremost factor that causes heavy yield reduction varying from 40 to 76 % in broad-cast seeded, 20 % in drill seeded and 11 to 20 % in transplanting in puddled fields. Malik et al. (2002) reported that uncontrolled weeds in rice can cause grain yield loss upto 89.9% as com-pared to weed free. Yield loss of rice due to uncontrolled weeds was 96 % in dry DSR, 61 % in wet DSR and 40 % in the machinery-transplanted crop (Kim and Pyon, 1998). Choubey et al. (2001) also reported that weeds are the major biotic constraints to crop pro-duction and in direct seeded rice they reduce the yield by 40 to 100 %. Yield losses without proper weed management can reach to 70-100 % in dry seeding versus only 10-35 % for machine-transplanted rice (Lee et al., 2002). The loss of yield in unweeded direct-seeded rice has been estimated to be 45-66 %, whereas it was 13% in transplanted rice (Thakur, 2006). Reported yield losses from weeds in DSR ranged from 20 to 88 % (Rao and Moody, 1994). Yield reduction upto 50 to 60 % and sometimes com-plete failure of the rice crop due to heavy infesta-

tion of weeds under direct seeded upland condi-tions has been reported by various researchers (Singh, 1988; Singh et al., 2002; Raju and Gangwar, 2004; Singh et al., 2005b; Singh et al., 2017). Methods of weed control: Integrated weed man-agement (IWM) is desirable for effective and sus-tainable weed control in Dry-DSR (Rao and Naga-mani, 2007; Rao et al., 2007). Tools available for IWM can be categorized broadly into (a) cultural, (b) chemical, (c) mechanical, and (d) allelopathic approach for weed control. Cultural methods of weed control Land levelling: Proper land preparation helps in reducing weed infestation by providing a weed free seed bed at the time of sowing. To achieve uni-form crop stand the field should be levelled before crop sowing. In Indo-Gangetic plains, a deviation of 8-15 cm in field level is observed due to traditional levelling. This results in poor crop establishment of rice due to unequal distribution of water in soil profile and inundation of newly germinating seedlings (Gopal et al., 2010). Laser land levelling ensures better crop establishment (Jat et al., 2009), precise water control and increased herbicide use efficiency (Chauhan, 2012). Time of sowing, seed rate and spacing: In northern India, rice is grown during the kharif sea-son before onset of monsoon. To optimize the use of monsoon rain, the optimum time for sowing DSR is about 10-15 days before onset of monsoon (Gopal et al., 2010; Kamboj et al., 2012; Kumar and Ladha 2011; Gopal et al., 2010). A seed rate

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Table 1. Different type of mulches, their suppressive ability on particular weeds and increase in yield.

Type of mulch Rate (t/ha)

Weeds Weed sup-pression (%)

Increase in yield (%)

Reference

Wheat mulch 4 Grass and BLW 54 22 (Singh et al ,. 2007) Plastic mulch Complex 69-77 45 (Mohtisham et al.,

2013) Paper mulch Echinochloa spp., Schoe-

noplectus mucronatus 61-97 (Wentao et al .,2003)

Maize mulch 5 Complex 48-56 32 (Mohtisham et al., 2013)

Sugarcane trash mulch

5 Complex 26-32 16 (Mohtisham et al., 2013)

Alfalfa 1 E.phyllopogon, Mono-choria vaginalis

~90 81 (Xuan et al., 2003)

Table 2. Common pre-emergence herbicides used in direct seeded rice in India.

S. No.

Name of the herbicide

Dose (kg/ha)

Time of application

References

1. Pendimethalin 0.75-1.0 PRE (Singh et al.,2016;Singh et al., 2017;Gopal et al., 2010) 2. Oxadiargyl 0.09-0.10 PRE (Singh et al., 2016; Singh et al.,2017) 3. Pyrazosulfron 0.015-0.020 PRE (Kaur and Singh, 2015) 4. Butachlor 1.0-1.50 PRE (Singh et al., 2016, Kaur and Singh, 2015) 5. Penoxsulam 0.030 PRE (Walia et al., 2012) 6. Pretilachlor 0.40-0.75 PRE (Walia et al., 2012) 7. Thiobencarb 1.25 PRE (Walia et al., 2012) 8. Flufenacet 0.08 PRE (Walia et al., 2012) 9. Anilofos 0.375 PRE (Kaur and Singh, 2015)

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of 20–25 kg/ha has been found optimum for bas-mati rice cultivars with a spacing of 20 cm (Yadav et al., 2007). High seed rates results in excessive vegetative growth thereby utilizing most of the resources be-fore anthesis and less accumulation of dry matter after anthesis (Wells and Faw, 1978). This results in lower N content in foliage (Dingkuhn et al., 1990) and results in sterility of spikelet and less grains per panicle (Kabir et al., 2008). Moreover, dense plant populations at high seed rates can create favourable conditions for diseas-es, e.g., sheath blight (Guzman and Nieto 1992; Mithrasena and Adikari 1986) and insects (e.g., brown plant hoppers) and make plants more prone to lodging due to weak stem (Islam et al., 2008). Lower seed rate can be used for high-tillering vari-eties and a little higher seed rate for medium-tillering varieties (Soo et al., 1989). Seeding depth is another important aspect which must be kept in mind. In DSR, seeding should be done with precision planters having depth control wheels. Seed depth plays an important role in germination and seedling emergence in DSR. Semi-dwarf varieties are highly sensitive to seed-ing depth due to their shorter mesocotyl as com-pared to conventional tall varieties (Blanche et al., 2009). The germination of seedling is decreased when seed is placed too deep or at shallow depth. When the seed is placed too deep, there are chances that the shoot tip will be damaged due to weak coleoptile, while if seeds are placed near surface, germination is affected by rapid drying of soil surface and high temperature near soil sur-face due to incoming solar radiation (Gopal et al., 2010). Maximum depth upto which rice seeds can be drilled is 2.5 cm, deeper than 2.5 cm results in uneven crop establishment (Kamboj et al., 2012). Stale seed bed technique: Stale seedbed tech-nique can be used to decrease weed seed bank from soil where a particular cropping system is followed year after year. This could be very useful in IGP where rice-wheat is the major cropping system. It depletes 5-10% of weed seeds present in soil. In stale seedbed after tillage, light irrigation is ap-plied to facilitate proper germination and emer-gence of weed seedlings. Single irrigation is given 15 days before sowing to maximize weed germi-nation and after that soil moisture is maintained at optimum level. A non-selective herbicide (glyphosate or paraquat) or mechanical method is used to kill emerged weeds (Anonymous, 2017). Stale seedbed can be very effective when weed species have low dormancy, are placed near soil surface (in Zero-tillage) and favourable environ-mental conditions (light, optimum temperature) are present (Chauhan, 2012).

Singh et al. (2009b) reported that using stale seedbed technique in direct seeded rice, weed density can be reduced by 53% over control. Chauhan and Johnson (2010) observed better weed control when stale seedbed with paraquat is used with zero-till because weed seeds placed deeper than 1cm do not emerges. Combined use of stale seedbed along with pendi-methalin gave effective control of weeds in DSR in in large-scale farmer participatory trials in India (Singh et al., 2005c). Mulching: Applying mulch on soil is another of controlling weeds in direct seeded rice. Besides conserving moisture mulch suppresses weeds, prevents soil erosion, add organic matter to soil, improve soil health and decrease fluctuations in diurnal temperature (Qin et al., 2010). Mulches are thought to supress weeds by physical obstruction to germinating weed seeds, block in-coming sunlight and by release of certain allelo-chemicals. Kumar et al. (2013) reported that prob-lematic weeds of DSR such as Echinochloa crusgalli, E. colona, Dactyloctenium aegyptium and Eclipta alba were sensitive to wheat straw used as mulch. Batish et al. (2007) claimed that when residue of Tagetes minuta L. was used as mulch it suppress-es growth of E. crus-galli and C. rotundus. Hong et al. (2004) reported through allelopathy certain plants like with Clerodendrum trichotomum Thunb., Datura stramonium L., Desmodium triflo-rum (L.) DC. and Melia azedarach L. were found to supress weeds in rice by 70-90%. Singh et al. (2007) studied the effect of weed sup-pression ability of weeds with wheat straw 4 t/ha spread uniformly at SVBPU and T and found that during early stage (30 DAS) mulch resulted into highest reduction in total weed density (54%) which may be due to inhibitory effect of allelo-chemicals released by wheat on weed seed ger-mination. Also wheat straw results in better weed control and gain in grain yield of rice. Wheat straw reduced grasses and BLW by 46% and 71% re-spectively, and increases grain yield of rice by 22%. This result in higher economic returns com-pared to control (Singh et al., 2007). Hamdi et al. (2001) reported that suppressive ef-fect of wheat straw on ryegrass may be through release of leachates and organic molecules may be involved. The straw generated in wheat crop can be best utilised by spreading over the surface. This will also solve the problem of straw management as burning straw in the IGP is another serious issue. Encouraging results with the use of straw mulch from previous crop have been reported by Taluk-der et al. (2006). Straw mulch from previous crop along with post emergence herbicides could be promising strategy to control weeds in direct seeded rice.

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Weed competitive cultivar: Weed-competitive cultivars can be a low cost but promising strategy to get higher yield and economic returns (Andrew et al., 2015). Varieties having good mechanical strength of coleoptile for rapid germination and higher seedling vigour to compete weeds are best suited for direct seeding (Jannink et al., 2000; Zhao et al., 2006). Ranasinghe (1995) conducted field experiments to identify morphological traits which provide com-petitive ability to rice plants against weeds. He found that rice-barnyard grass competition varies significantly with the morphology of rice cultivar. Cultivar which attains more plant height, leaf area and higher dry matter accumulation during seed-ling stage and more plant height and leaf area at the time of maturity offers more competition to the weeds. Better developed roots, high leaf area index and tillering capacity were the characters associated with weed suppressive rice cultivars (Fofana and Rauber, 2000). Perera et al. (1992) observed that under high crop-weed competition the root growth, root biomass and nutrient uptake is reduced in rice cultivars. Gealy and Moldenhauer (2012) reported that weed suppressive rice cultivars have twice root biomass than those of non-suppressive types. Due to higher root biomass and root proliferation, weed suppressive cultivars competed better for resources with weeds and reduced weed loss by 44% and weed prevalence by 30% as compared to non-suppressive cultivars (Gealy and Molden-hauer, 2012). Therefore varieties suitable for direct seeded re-quire characters like efficient root system for bet-ter anchorage and to draw moisture from deeper soil layers during peak evaporation demands (Clark et al., 2000; Pantuwan et al., 2002) and a wider window of sowing time. In Punjab and Har-yana region, variety PUSA-1121, PR-115, PAU-201 etc. are suited for direct seeding. Crop rotation: Crop rotation is very useful in con-trolling weeds. There are certain crop associated weeds which can be controlled simply by chang-ing cropping system. Changing cropping system shifts the weed flora in which some weeds disap-pear and new weeds emerges. Singh et al. (2008) studied change in composition of weeds, weed

density and weed dry weight when rice-wheat cropping sequence is changed. They found that minimum weed density was recorded in rice- wheat-green gram sequence followed by rice-wheat, rice-chickpea and rice-pea sequence. Changing rice-wheat rotation also helps in identifi-cation of weedy rice. By rotating rice with soy-bean, mungbean, Kharif maize or cotton etc., weedy rice can be controlled because other herbi-cides and cultural practices can be used which cannot be used in rice (Singh et al., 2013). Chhokar et al. (2008) reported that introduction of potato and pea in between rice and wheat can also improve weed control without herbicide appli-cations. Brown manuring: Brown manuring with sesbania in direct seeded rice can be a good option to con-trol weeds, improve soil health and get higher yield. Seeds of sesbania 20 kg/ha can be drilled in between the rows of direct seeded rice 3 days after sowing of rice and sprayed with 2,4-D ethyl ester 0.50 kg/ha to produce sesbania brown ma-nure. Nawaz et al. (2017) evaluated five different rice-wheat cropping systems and found that brown manuring in direct seeded rice with sesbania de-creased weed density by 41-56 % and weed bio mass by 62-75% than sole direct seeded rice. Seed priming: Seed priming are primarily aimed at hydration of seeds for a specific period of time to complete pre-germinative metabolic process but emergence of radicle is avoided. Priming may be done with water (hydro-priming), salt solution-NaCl (halo priming) or use of moist sand (sand matric priming). Priming increases germination percentage, gave uniform germination, improves resistance towards water and temperature stress, and increases the yield. Increased vigour in direct seeded Aeron 1 by dif-ferent priming treatments was observed by Jurai-mi et al. (2012). They reported primed seeds pro-duced vigorous seedling with 50% higher vigour index than unprimed seeds Anwar et al. (2012) claimed that primed seeds reduce weed dry weight by 22 to 27 % mainly due to good crop establishment with vigorous seed-lings and quick canopy development. They also found that primed rice seeds produce 0.4t/ha more yield over control.

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Table 3. Common post-emergence herbicides used in direct seeded rice in India

Sl. No

Name of the herbicide Dose (kg/ha) Time of appli-cation (DAS)

Reference

1. Bispyribac-sodium 0.025 25-30 (Kaur and Singh, 2015; Walia et al., 2008)

2. Fenoxaprop-p-ethyl 0.06-0.075 25-30 (Upasani and Barla, 2014) 3. Ethoxysulfuron 0.015-0.0175 25-30 (Upasani and Barla, 2014) 4. Chlorimuron-ethyl+ met-

sulfuron-methyl 0.002-0.004 25-30 (Singh et al., 2010; Singh et al., 2017)

5. Acifluorfer 0.60 20-30 (Sankula et al.,1997) 6. 2,4-D 1.0 30 (Angiras and Attri, 2002)

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Mechanical and manual methods of weed con-trol: Controlling weeds through any physical activ-ity that inhibits growth of weeds is mechanical control. Mowing: Mowing is removing or cutting shoot of weeds by using sickle or mower. It is successful for controlling annual weeds while less practiced in case of perennial weeds because perennial weeds have stored food in below ground parts (rhizomes, stolones etc.) and come in several flushes. Mowing must be done before flowering or seed setting to prevent dispersal of seeds. Weed thus obtained should be buried deep or burnt to remove viability of weed seeds (Matloob et al., 2015). Mechanical weeder: The mechanical methods control weeds and gave yield at par with chemical control provided they are done properly. Mechani-cal weeding is not practiced in IGP due to labour and economic constraint. Muthukrishnan and Purushothaman (1992) report-ed that HW twice at 25 and 45 DAS effectively controlled the weeds, resulting in higher grain yield over un-weeded check. Mehta et al. (1993) observed that HW twice, at 20 and 30 DAS, pro-duced rice grain yield of 3.2 t/ha at par with weed free ( HW four times) yielding 3.3 t/ha and higher than one HW ( 2.5 t/ha) and weedy (1.0 t/ha). Singh et al. (2003) reported from Pantnagar, India that pendimethalin at 1.0 kg/ha along with farm waste as mulch (7.5 t/ha) supplemented with one HW at 45 DAS decreased weed count, weed bio-mass with highest weed control efficiency (91.3%) which was comparable with HW thrice at 30, 60 and 90 DAS (farmers‟ practice). Manual weeding can be implemented only when weeds have reached a sufficient size to be pulled and it has an inherent opportunity cost. Manual weeding is therefore often practiced late as evi-dent by yield loss comparisons of the effects of manual weeding at 21-30 DAS with those from the use of early post-emergence herbicides (Singh et al., 2005a). Labour scarcity, high labour cost, poor weather conditions and the presence of perennial weeds that breaks down on pulling may all lead to lower efficiency of hand weeding. Mechanical weeding using simple implements remains a practical and economic method for many small and marginal farmers of Asia and Afri-ca. Mechanical weeding is almost universally practised on row-seeded rice since inter row culti-vation with either hand tools or animal traction equipment reduces time in weeding and minimiz-es crop damage. Sarma and Gogoi (1996) reported that in rain-fed upland rice in India, a manually operated peg-type dry-land weeder which is operated manually (with a straight-line peg arrangement) has shown excel-lent performance across a wide range of soil types

with varying soil moisture levels and weed intensi-ty providing a labour saving of ~ 57% compared with hand weeding ( 127 person-days/ha). Chemical method of weed control: Labour una-vailability, increasing labour costs, and the press-ing need to raise yield and maintain profit on a progressively limited land base have been the major drivers for farmers to seek alternatives to manual weeding. Herbicides are one such alterna-tive. Effective weed management practices are an important pre-requisite in DSR culture, with herbi-cide application seemingly indispensable (Azmi et al., 2005). The trend for an increase in herbicide use has been reinforced by the spread of DSR (Naylor, 1994). Pre-emergence herbicides: Different pre-emergence herbicides are used for controlling weeds in direct seeded rice in India (Table 2.). Among them, pendimethalin 1.0 kg/ha, oxadiargyl (0.10 kg/ha) and pyrazosulfron (0.02 kg/ha) were found to give effective weed control (Gupta et al., 2006a; Rao and Nagamani, 2007; Singh et al., 2009; Gopal et al., 2010; Singh et al., 2017). Pendimethalin is a selective herbicide effective against most annual grasses and several annual broad leaves weeds. It belongs to chemical class of dinitroaniline. It acts via inhibition of microtubule formation, disrupting cell division and causing mi-crofibril disorientation, so it‟s a germination inhibi-tor. Pendimethalin controls Echinochloa spp. more effectively as compared to Cyperus spp. Pendime-thalin at 0.90 kg/ha provided excellent control of weedy rice and best control of grassy weeds (Joseph et al., 1990), whereas Malik et al. (2002) reported that pendimethalin was effective only against Echinochloa spp., Cyperus iria and Com-melina banghalensis. It shows poor efficacy against Leptochloa chinensis, another predomi-nant weed in direct seeded rice (Singh et al., 2017). Singh et al. (2016) evaluated three pre-emergence herbicides pendimethalin 1.0 kg/ha, butachlor 1.0 kg/ha and oxadiargyl 0.09 kg/ha and found weed density after application of these herbicides were 10-13, 15 and 16-23 plants/m2 respectively compared to 51 plants/m2 in weedy check at Taraori location. At Madhuban location, highest grain yield of direct seeded rice (3.43 t/ha) was obtained with pendimethalin 1.0 kg/ha PRE fb

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Fig. 1. Allelochemicals isolated from rice (Olofsdotter et al., 1995; Chung et al., 1997; Dilday et al., 1998; Hassan et al., 1998)

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bispyribac-sodium 0.025 kg/ha and azimsulfuron 0.0225 kg/ha POST which was comparable under weed free (3.5 t/ha). Kaur and Singh (2015) evaluated seven pre-emergence (pendimethalin 0.75 g/ha, Butachlor 1.50 kg/ha, Thiobencarb 1.50 kg/ha, Anilofos 0.375 kg/ha, Pretilachlor 0.75 kg/ha, Oxadiargyl 0.09 kg/ha, Pyrazosulfuron-ethyl 0.015 kg/ha) herbicides for their efficacy against weeds in DSR. Application of pendimethalin 0.75 kg/ha PRE pro-duce significantly lower weed density of Echi-nochloa spp. at 30 DAS than all other pre emer-gence herbicides. Similarly, the density of Cyperus spp. was similar in all pre-emergence herbicides. However, the weed dry matter of Cyperus spp. in Pyrazosulfuron-ethyl 0.015 kg/ha treated plots was at par with unweeded at 30 DAS. Post-emergence herbicides: In direct seeded rice, more than one flush of weeds occurs during crop duration. Pre emergence herbicides gave effective control during early stage of crop growth and post emergence herbicides during the second flush of weeds. If weeds were not controlled properly, they can cause significant qualitative and quantitative loss in grain yield. A single herbi-cide cannot give effective weed control throughout crop growth period so sequential herbicide appli-cation is done. A list of common post emergence herbicides used in direct seeded rice in India is given in Table 3. Walia et al. (2008) claimed that application of bispyribac-Na @ 0.025 kg/ha controlled all type of weeds in direct seeded rice and was found very effective against problematic weeds of DSR i.e. Echinochloa spp. and Cyperus spp. Also, Kaur and Singh (2015) reported that application of bispyribac-Na 0.025 kg/ha POST after six pre-emergence herbicides (butachlor, thiobencarb, anilofos, pretilachlor, oxadiargyl and pyrazosulfu-ron-ethyl) produced lower weed density than the-se six pre-emergence herbicides applied alone. Singh et al. (2017) at Kaul, Kaithal (Haryana) claimed that Leptochloa chinensis can be con-trolled effectively by fenoxaprop-p-ethyl 0.067 kg/ha having weed control efficiency (WCE) of 92 % than bispyribac-Na 0.025 kg/ha with WCE of 38 % in direct seeded rice (DSR). Singh et al. (2004) at Pantnagar also reported good control of L. chinen-sis by fenoxaprop-p-ethyl 0.056 kg/ha while its efficacy against Echinochloa spp. and Cyperus spp. was poor than bispyribac-Na with WCE of 40 %. Singh et al. (2010) evaluated azimsulfuron 0.025-0.030 kg/ha at 25 DAS alone and tank mixed with chlorimuron-ethyl+ metsulfuron-methyl 0.004 kg/ha and reported that tank mixing of chlo-rimuron-ethyl+ metsulfuron-methyl 0.004 kg/ha does not improves the efficacy of azimsulfuron 0.025-0.030 kg/ha against grasses weeds. Azimsulfuron 0.025-0.030 kg/ha alone at 25 DAS

gave effective control of BLW (Broad leaf weeds) and sedges especially Cyperus rotundus but poor control of grasses. Mishra and Singh (2008) evaluated two pre emer-gence herbicides i.e., pendimethalin 1.0 kg/ha and pretilachlor 0.75 kg/ha followed by 1 HW at 30 DAS or 2, 4-D (0.05 kg/ha) + fenoxaprop (0.07 kg/ha) and reported that these treatments being at par were effective against weeds and gave signifi-cantly higher grain yield (3.07, 3.25, 3.23 and 3.14 t/ha, respectively) and benefits (B:C ratio of 1.75, 1.75, 1.86 and 1.71, respectively) than weedy check (1.36 t/ha and 0.95). Singh et al. (2006) studied efficacy of herbicides in direct seeded rice cultivated in FIRBS (furrow irri-gated raised bed planting system) and reported that application of fenoxaprop 0.050 kg/ha + eth-oxysulfuron 0.018 kg/ha at 21 DAS and pendime-thalin 1.0 kg/ha PRE fb chlorimuron-ethyl+ metsul-furon-methyl 0.004 kg/ha at 21 DAS were effective against mixed weed flora (WCE of 90 and 84%, respectively) and economical also (Net income of 115 and 97 US $, respectively). Mahajan et al. (2009) reported that application of bispyribac-Na 0.025 kg/ha and penoxsulam 0.025 kg/ha effec-tively controlled all the weeds in aerobic direct seeded rice (ADSR) with WCE of 85 and 67 %, respectively and grain yield were similar with con-ventional puddled transplanted rice (CPTR) (25.69 and 20.76 q/ha under ADSR and 30.02 and 28.58 q/ha under CPTR). Mahajan and Timisina (2011) claimed that appli-cation of pendimethalin 1.0 kg/ha PRE fb bispyri-bac-Na 0.030 kg/ha 18 DAS or pendimethalin 1.0 kg/ha PRE fb bispyribac-Na 0.030 kg/ha 18 DAS + HW 45 DAS gave better weed control (WCE of 81 and 91%, respectively compared to pendimethalin 1.0 kg/ha PRE fb+ HW 45 DAS), higher grain yield (5.32 and 6.11 t/ha, respectively), higher water productivity and profitability in direct seeded rice. Walia et al. (2008) reported that application of pendimethalin 0.75 kg/ha PRE followed by bispyri-bac-Na 0.25 kg/ha or azimsulfuron 0.020 kg/ha or 2,4-D 0.50 kg/ha at 30 DAS resulted in better weed control (WCE of 87, 84 and 78%, respec-tively) and higher grain yield of rice (5618, 4747 and 4675 kg/ha, respectively). Application of pendimethalin 0.75 kg/ha PRE fb bispyribac-Na 0.025 kg/ha resulted in 372 % increase in grain yield as compared to unweeded control (1191 kg/ha). Application of pendimethalin provided effec-tive control of non-predominant paddy weeds, whereas bispyribac-Na controlled typical predomi-nant paddy weeds including Echinochloa colona and all Cyperus spp. Singh et al. (2017) reported that pendimethalin 1.0 kg/ha fb bispyribac-Na and chlorimuron-ethyl+ metsulfuron-methyl 0.004 kg/ha gave effective weed control (WCE of 75.4%) with higher grain yield and profitability at par with weed free (3.97

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and 4.12 t/ha and 2.37 and 2.01, respectively). Allelopathy: Recent studies showed that rice plants and weeds also compete through allelopa-thy. Olofsdotter (2001) studied allelopathic poten-tial of 111 rice cultivars on weeds in Philippine‟s and reported that dry weight of weeds reduced upto 34 % after 8 weeks of seeding. The reduction in weeds dry weight is due to allelochemicals re-leased by these rice cultivars (Olofsdotter et al., 2002). Kato-Noguchi et al. (2011) identified 3-hydroxy-β-ionone and 9-hydroxy-4-megastigmen-3-one (Fig. 1) as main allelochemicals in Kartik-shail and BR 17, two high yielding rice cultivars of Bangladesh. Allelopathic potential of many rice cultivars like BR17 against Echinochloa crus-galli and E. colo-num had already been reported in various studies (Farooq et al., 2008; Farooq et al., 2011; Jabran and Farooq, 2013). -----Several rice cultivars through release of allelochemical had been found to suppress predominant weeds of rice, such as E. crus-galli (Jensen et al., 2001; Seal and Prat-ley, 2010), Cyperus difformis (Seal and Pratley, 2010), Sagittaria montevidensis (Seal and Pratley, 2010; Seal et al., 2004). Seal and Pratley (2010) evaluated the allelopathic multi-weed suppression of 27 different rice culti-vars against five major aquatic weeds of Australia and found that cultivar Amaroo inhibited Alisma-taceae weeds by an average of 97%, whereas Echinochloa crus-galli was inhibited by 72%. A non allelopathic cultivar, Langi stimulated root growth of E. crus-galli by almost 20 %. In India not much work is done to exploit the rice‟s allelopathic property for weed control in direct seeded rice. Cultivars with improved allelopathic potential can be developed which compete better with weeds and lowers the dependence on herbi-cides. So, there is wide scope to identify, develop and exploit cultivars with higher allelopathic poten-tial in proper cropping systems.

Conclusion

Weeds are the major biotic factors which hinder the growth and yield of direct seeded rice. Con-trolling weeds is pivotal for getting good grain yield of rice. Not a single weed control method is ecological viable and sustainable both ecologically as well as economically. Therefore, integrating different weed control methods on the basis of climatic conditions, edaphic factors, weed flora present and cultivars, effective weed management on a long term sustainable basis can be achieved. New weed control approach like allelopathy can be used along with other weed control methods to further reduce the losses caused by the weeds in direct seeded rice.

REFERENCES

Aggarwal, G.C., Sindhu, A.S., Sekhlon, N.K., Sandhu, K.S. and Sur, H.S. (1995). Puddling and N manage-

ment effects on crop response in rice-wheat cropping system. Soil and Till. Rese. 36:129-139.

Andrew, K. S., Storkey, J. and Sparkes, D. L. (2015). A review of the potential for competitive cereal cultivars as a tool in integrated weed management. Weed Rese. 55: 239-248.

Angiras, N. N. and Rana, S. S. (1998). Butachlor safen-er combinations for weed control in direct‐seeded puddled rice. Inter. Rice Rese. Notes. 23, 46.

Anonymous ( 2016). Indiastat base. Retreived from https://www.india.stat.com

Anonymous (2017). International Rice Research Insti-tute, Rice Knowledge Book. Los Banos, Philippines. Accessed on 13.10.2017. url: http://www.knowledgebank.irri.org/step-by-step-production/growth/weed-management/stale-seedbed-technique.

Anwar, M. P., Juraimi, A. S., Puteh, A., Selamat, A., Rahman, M. M. and Samedani, M. (2012). Seed prim-ing influences weed competitiveness and productivity of aerobic rice. Acta Agricul. Scand. 62:499-509.

Azmi, M., Chin, D. V., Vongsaroj, P. and Johnson, D. E. (2005). Emerging issues in weed management of direct‐seeded rice in Malaysia, Vietnam, and Thai-land. In „„Rice Is Life: Scientific Perspectives for the 21st Century‟‟ (K. Toriyama, K. L. Heong, and B. Har-dy, Eds.), pp. 196 198. International Rice Research Institute, Los Ban˜os, Philippines, and Japan Interna-tional Research Center for Agricultural Sciences, Tsu-kuba, Japan.

Batish, D. R., Arora, K., Singh, H. P., Kohli, R. K. (2007). Potential utilization of dried powder of Tagetes minu-taas a natural herbicide for managing rice weeds. Crop Prot. 26: 566-571.

Bhurer, K.P., Yadav, D.N., Ladha, J.K., Thapa, R.B. and Pandey, K.R. (2013). Efficacy of various herbicides to control weeds in dry direct seeded rice (Oryza sativa L.). Global Journal of biology, agriculture and health sciences. 2(4):205-212.

Blanche, B., Harrell, D. and Saichuk, J. (2009). General Agronomic Guidelines. In “Louisiana rice production handbook 2009” (J. Saichuk, ed.), pp 3–15, Pub. 2321 (3M) 6/09 Rev.

Chauhan, B. S. and Johnson, D. E. (2010). The role of seed ecology in improving weed management strate-gies in the tropics. Advan. in Agron. 105: 221–262.

Chauhan, B. S. and Yadav, A. (2013). Weed manage-ment approaches for direct seeded rice in India: a review. Ind. J. Weed Sci. 45 (1):1-6.

Chauhan, B.S. (2012). Weed ecology and weed man-agement strategies for dry-seeded rice in Asia. Weed Technol. 26:1–13.

Chhokar, R.S., Sharma, R.K., Singh, R.K. and Gill, S.C. (2008). Herbicide resistance in little seed canary grass (Phalaris minor) and its management. In: Pro-ceedings of the 14th Australian Agronomy Conference, Adelaide, South Australia,106p.

Choubey, N.K., Kolhe, S.S. and Tripathi, R.S. (2001). Relative performance of cyhalofop-butyl for weed control in direct-seeded rice. Ind. J. Weed Sci. 33(3&4): 132-135.

Chung, I.M., Kim, K.H., Ahn, J.K and Ju, H.J. (1997). Allelopathic potential evaluation of rice cultivars on Echinochloa crus-galli. Korean J. Weed Sci. 17:52–58

Clark, L. J., Aphale, S. L. and Barraclough, P. B. (2000). Screening the ability of rice roots to overcome the mechanical impedance of wax layers: Importance of test conditions and measurement criteria. Plant and

Singh A. et al. / J. Appl. & Nat. Sci. 10 (2): 779 - 790 (2018)

787

Soil. 219:187–196. Datta, D. (1986). Technology development and the

spread of direct seeded flooded rice in South-East Asia. Experi. Agri. 22(4): 417-426.

Dawe, D. (2005). Increasing water productivity in rice-based systems in Asia-Past trends, current problems, and future prospects. Plant Prod. Sci. 8(3): 221-230.

Dhillon, B. S., Kataria, P. and Dhillon, P. K. (2010). Na-tional food security vis-à-vis sustainability of agricul-ture in high crop productivity regions. Current Sci. 98:33-36.

Dilday, R.H., Yan, W.G., Moldenhauer, K.A.K. and Gra-vois, K.A. (1998). Allelopathic activity in rice for con-trolling major aquatic weeds. In: Olofsdotter M (ed.) Allelopathy in rice. International Rice Research Insti-tute, Manila, pp 7–26.

Dingkuhn, M., Schnie, H. F., De Datta, S. K., Wijangco, E. and Doeffling, K. (1990). Diurnal and developmen-tal changes incanopy gas exchange in relation to growth in transplanted and direct seeded flooded rice. Aust. J. Plant Physio. 17:119– 134.

Farooq, M., Jabran, K., Cheema, Z.A., Wahid, A. and Siddique, K. H. M. (2011). The role of allelopathy in agricultural pest management. Pest Manag. Sci. 67: 493-506.

Farooq, M., Jabran, K., Rehman, H. and Hussain, M. (2008). Allelopathic effects of rice on seedling devel-opment in wheat, oat, barley and berseem. Allelo. J. 22: 385-390.

Fofana, B. and Rauber, R. (2000). Weed suppression ability of upland rice under low input conditions in West Africa. Weed Rese. 40:271-280.

Gealy, D.R. and Moldenhauer, K.A. (2012). Use of 13C isotope discrimination analysis to quantify distribution of barnyardgrass and rice roots in a four-year study of weed-suppressive rice. Weed Sci. 60:133-142.

Giri, G.S. (1998). Effect of rice and wheat establishment techniques on wheat grain yield. In Hobbs PR, Bhan-dri, Raj, ediors. Proceedings of rice-wheat research project workshop, India. pp 65-68.

Gopal, R., Jat, R.K., Malik, R.K., Kumar, V., Alam, M.M., Jat, M.L., Mazid, M.A., Saharawat, Y.S., McDonald, A. and Gupta, R. (2010). Direct Dry Seeded Rice Production Technology and Weed Management in Rice Based Systems. Technical Bulletin. International Maize and Wheat Improvement Center, New Delhi, India, p. 28.

Gupta, R. K, Ladha, J. K, Singh, S., Singh, R., Jat, M. L., Saharawat, Y., Singh, V. P., Singh, S. S., Singh, G., Sah, G., Gathala, M. and Sharma, R. K. (2006). Production Technology for Direct Seeded Rice. Tech-nical Bulletin Series 8. In “Rice–Wheat Consortium for the Indo-Gangetic Plains, New Delhi, India,” 14pp.

Guzman Garcia, P. and Nieto Illidge, L. (1992). New densities and fertilization to decrease Rhizoctonia solani. Rice. 41, 10-14.

Hamdi, B.A., Inderjit, Olofdotter, M. and Streibig, J.C. (2001). Laboratory bioassay of phytotoxicity. Agron. J. 93:43-48.

Hassan, S.M., Aidy, I.R., Bastawisi, A.O. and Draz, A.E. (1998). Weed management using allelopathic rice varieties in Egypt. In: Olofsdotter M (ed) Allelopathy in rice. International Rice Research Institute, Manila, pp 27–37.

Hira, G. S. and Khera, K. L. (2000). Water resource management in Punjab under rice-wheat production system. Ludhiana, Punjab, India: Department of Soils,

Punjab Agricultural University. Research Bulletin No. 2/2000.

Hobbs, P.R. and Gupta, R.K. (2000). Sustainable re-source management in intensively cultivated irrigated ricewheat cropping systems of the Indo-Gangetic Plains of South Asia: Strategies and options. In “International Conference on Managing Natural Re-sources for Sustainable Production in 21st Century”, 14-18 February 2000, New Delhi, India, Pp. 584-592.

Hong, N., Xuan, T., Tsuzuki, E., Terao, H., Matsuo, M. and Khanh, T. (2004). Weed control of four higher plant species in paddy rice fields in Southeast Asia. J Agron. Crop Sci. 190:59-64.

http://a-c-s.cofex.com/crops/2009am/webprogram pa-per53386.html.

Islam, M. F., Sarkar, M. A. R., Islam, M. S., Parveen, S. and Hossain, M. S. (2008). Effects of crop establish-ment methods on root and shoot growth, lodging be-havior of Aus rice. Inter. J. Biol. Rese. 5:60–64.

Jabran, K. and Farooq, M. (2013). Implications of poten-tial allelopathic crops in agricultural systems. In: Cheema, Z.A., Farooq, M., Wahid, A. (Eds.), Allelopa-thy, Current Trends and Future Applications. Springer Berlin, Heidelberg, pp. 349-385

Jannink, J. L., Orf, J. H., Jordan, N. R. and Shaw, R. G. (2000). Index selection for weed-suppressive ability in soybean. Crop Sci. 40:1087–1094.

Jat, M.L., Gathala, M.K., Ladha, J.K., Saharawat, Y.S., Jat, A.S., Vipin, K., Sharma, S.K., Kumar, V., and Gupta, R. K. (2009). Evaluation of precision land lev-eling and double zero-till systems in the rice-wheat rotation: Water use, productivity, profitability and soil physical properties. Soil Till. Rese. 105: 112–121.

Jensen, L.B., Courtois, B., Shen, L., Li, Z., Olofsdotter, M. and Mauleon, R.P. (2001). Locating genes control-ling allelopathic effects against barnyardgrass in up-land rice. Agron. J. 93:21-26.

Joseph, K., Tomy, P.J. and Nair, N.R. (1990). Relative efficacy of different herbicides for control of weeds in dry seeded low land rice. Oryza. 27(2): 199-201.

Juraimi, A. S., Anwar, M. P., Selamat, A., Puteh, A. and Man, A. 2012. The influence of seed priming on weed suppression in aerobic rice. Pak. J. Weed Sci. Rese. 18: 257-264.

Kabir, M. H., Saha, A., Mollah, I. U., Kabir, M. S. and Rahman, F. (2008). Effect of crop establishment methods and weed management practices on the productivity of boro rice in lowland ecosystem. Inter. J. Bio. Rese. 5:42–51.

Kamboj, B. R, Kumar, A., Bishnoi, D. K., Singla, K., Ku-mar, V., Jat, M. L., Chaudhary, N., Jat, H. S., Gosain, D. K., Khippal, A., Garg, R., Lathwal, O. P., Goyal, S. P., Goyal, N. K., Yadav, A., Malik, D. S., Mishra, A. and Bhatia, R. (2012). Direct Seeded Rice Technolo-gy in Western Indo-Gangetic Plains of India: CSISA Experiences. CSISA, IRRI and CIMMYT 16 pp

Kato-Noguchi, H., Salam, M. A. and Suenaga, K. (2011). Isolation and identification of potent allelopa-thic substances in a traditional Bangladeshi rice culti-var Kartikshail. Plant. Prod. Sci.14(2): 128-134.

Kaur, S. and Singh, S. (2015). Bio-efficacy of different herbicides for weed control in direct-seeded rice. Ind. J. Weed Sci. 47(2):106-109.

Kim, H.H. and Pyon, J.Y. (1998). Weed occurrence and yield loss due to weeds in different direct seeded rice paddy fields. Kor. J. Weed Sci. 18(1): 12-19.

Kumar, V. and Ladha, J. K. (2011). Direct seeding of

Singh A. et al. / J. Appl. & Nat. Sci. 10 (2): 779 - 790 (2018)

788

rice: recent developments and future research needs. Advan. Agron. 111: 297-413.

Kumar, V., Ladha, J.K. and Gathala, M.K. (2009). Direct drill-seeded rice: A need of the day. In “Annual Meet-ing of Agronomy Society of America, Pittsburgh, No-vember 1-5, 2009”

Kumar, V., Singh, S., Chhokar, R.S., Malik, R.K., Brainard, D.C. and Ladha, J.K. (2013). Weed man-agement strategies to reduce herbicide use in zero-till rice-wheat cropping systems of the Indo-Gangetic Plains. Weed Tech. 27: 241-254.

Ladha, J.K., Kumar, V., Alam, M.M., Sharma, S., Gathala, M., Chandra, P., Saharawat, Y.S. and Bal-asubramanian, V. (2009). Integrating crop and re-source management technologies for enhanced productivity, profitability, and sustainability of the rice-wheat system in South Asia. in “ Integrated Crop and Resource Management in the Rice-Wheat System of South Asia”. (J. K. Ladha, Y. Singh, O. Erenstein, and B. Hardy, Eds.), pp. 69-108. International Rice Re-search Institute, Los Banos, Philippines.

Lee, M.H., Kim, J.K., Kim, S.S. and Park, S.T. (2002). Status of dry-seeding technologies for rice in Korea. In: Pandey et al. (eds.) Direct Seedling: Research and Strategies and Opportunities. Proceedings of the International Workshop on Direct Seeding in Asian Rice Systems: Strategic Research Issues and Oppor-tunities, 25-28 Jan., 2000, Bangkok, Thailand. IRRI. pp. 161-176.

Mahajan, G. and Timsina, J. (2011). Effect of nitrogen rates and weed control methods on weeds abun-dance and yield of direct-seeded rice. Arch. Agro. Soil Sci. 57(3): 239-250.

Mahajan, G., Chauhan, B.S. and Johnson, D.E. (2009). Weed management in aerobic rice in north western Indo-Gangetic plains. J. Crop Impro. 23(4): 366-382.

Maity, S.K. and Mukherjee, P.K. (2008). Integrated weed management in dry direct-seeded rice (Oryza sativa L.). Ind. J. Agro. 53(2): 116-120.

Malik, M., Singh, R., Singh, G., Singh, R.K. and Yadav, S.K. (2002). Evaluation of dithiopyr for control of weeds in direct-seeded rice. Ind. J. Weed Sci. 34(3&4): 287-289.

Matloob, A., Khaliq, A. and Chauhan, B. S. (2015). Weeds of direct-seeded rice in Asia: problems and opportunities. Advan. Agro.130: 291-336.

Mehta, R.K., Singh, G. and Singh, O.P. (1993). Weed management in rainfed lowland rice. Ind. J. Weed Sci. 25(2): 99-101.

Mishra, J.S. and Singh, V.P. (2008). Integrated weed management in dry-seeded irrigated rice (Oryza sati-va L.). Ind. J. Agro. 53(4): 299-305.

Mithrasena, Y. J. P. K. and Adikari, W. P. (1986). Effect of density on sheath blight (ShB) incidence. Interna-tional Rice Research Notes. 11, 20-21.

Mohtisham, A., Ahmad, R., Ahmad, Z. and Aslam, M.R. (2013). Effect of different mulches techniques on weed infestation in aerobic rice (Oryza sativa L.). American-Eurasian Journal of Agriculture and Envi-ronmental Science. 13:153-157.

Moody, K. (1983). The status of weed control in Asia. FAO. Plant Protection Bulletin. 30: 119-120.

Moody, K. and Mukhopadhyay, K. (1982). Weed control in dry seeded rice-problems, present status, research direction. In: Rice Research Strategies For The Fu-ture. International Rice Research Institute, Manila, Philippines. pp 147-158.

Muthukrishnan, P. and Purushothaman, S. (1992). Ef-fect of irrigation regime, weed control and biofertilizers on growth and yield of rice. Ind. J. Weed Sci. 24(3&4): 26-29.

Nawaz, A., Farooq, M., Lal, R., Rehman, A., Hussain, T. and Nadeem, A. (2017). Influence of sesbania brown manuring and rice residue mulch on soil health, weeds and system productivity of conservation rice–wheat systems. Land Degra. & Devel. 28:1078-1090.

Naylor, R. (1994). Herbicide use in Asian rice produc-tion. World Devel. 22: 55-70.

Olofsdotter, M. (2001). Rice- a step toward to use alle-lopathy. Agron. J. 93(1): 3-8.

Olofsdotter, M., Jensen, L. and Courtois, B. (2002). Im-proving crop competitive ability using allelopathy-an example from rice. Plant Breed. 121: 1-9.

Olofsdotter, M., Navarez, D. and Moody, K. (1995). Alle-lopathic potential in rice (Oryza sativa L.). Ann. Appl. Biol. 127:543–560.

Pandey, S. and Velasco, L. (2002). Economics of direct-seeding in Asia: Patterns of adoption and research priorities. In, “Rice is life: Scientific Perspective for the 21st Century”. Toriyama, K., Heong, K. L., Hardy, B., editors. Los Banos Philippines: International Rice Research Institute, and Tsukuba (Japan): Japan Inter-national Rice Research Center for Agricultural Scienc-es. pp.3-4.

Pantuwan, G., Fukai, S., Cooper, M., Rajatasereekul, S. and O‟Toole, J. C. (2002). Yield response of rice (Oryza sativa L.) genotypes to different types of drought under rainfed lowlands. Plant factors contrib-uting to drought resistance. Field Crops Rese. 73:181–200

Perera, K., Ayres, P. and Gunasena, H. (1992). Root growth and the relative importance of root and shoot competition in interactions between rice (Oryza sativa L.) and Echinochloa crus-galli. Weed Rese. 32:67-76.

Qin, J., Hu, F., Li, D., Li, H., Lu, J. and Yu, R. (2010). The effect of mulching, tillage and rotation on yield in non-flooded compared with flooded rice production. J. Agro. and Crop Sci. 196:397-406.

Raju, R.A. and Gangwar, B. (2004). Bioefficacy of new promising herbicides on weed management in direct sown puddle rice. Extended summaries vol. 2, Inter-national symposium on rice held at Hyderabad (A.P.), India, Oct. 4-6, 2004. pp. 340.

Ranasinghe, L. L. (1995). Enhancement of the weed competitive ability of rice (Oryza sativa L.) cultivars. Ph. D. thesis.

Rao, A.N. and Moody, K. (1994). Ecology and manage-ment of weeds in farmers‟ direct seeded rice (Oryza sativa L.) fields. Consultancy report of work done from 1st July to 31st December, 1994. Los Banos (Philippines): IRRI. pp. 81.

Rao, A.N. and Nagamani, A. (2007). Available technolo-gies and future research challenges for managing weeds in dry-seeded rice in India. In: “Proceeding of the 21st Asian Pacific Weed Society Conference.” from 2 to 6 October 2007, Colombo, Sri Lanka, pp. 391-491.

Rao, A.N., Johnson, D.E., Shivprasad, B., Ladha, J.K. and Mortimer, A.M. (2007). Weed management in direct-seeded rice. Advan. Agro. 93: 153-255.

Rashid, M.H., Alam, M.M., Khan, M.A.H. and Ladha, J.K. (2009). Productivity and resource use of direct (drum) seeded and transplanted rice in puddle soils in rice-rice and rice-wheat ecosystem. Field Crops Rese.

Singh A. et al. / J. Appl. & Nat. Sci. 10 (2): 779 - 790 (2018)

789

113: 274-281 Saha, S. (2006). Efficacy of herbicides in wet direct-

sown summer rice. Ind. J. Weed Sci. 38(1&2): 45-48. Sankula, S., Braverman, M. P. and Linscombe, S. D.

(1997). Glufosinate‐resistant, BAR‐ transformed rice (Oryza sativa) and red rice (Oryza sativa) response to glufosinate and in mixtures. Weed Tech. 11, 662–666.

Sarma, A. and Gogoi, A. K. (1996). Performance of different weeders in rainfed upland rice (Oryza sativa L.). Ind. J. Weed Sci. 33: 178-182.

Seal, A. and Pratley, J. (2010). The specificity of allelop-athy in rice (Oryza sativa). Weed Rese. 50, 303-311.

Seal, A.N., Pratley, J.E., Haig, T., Lewin and L.G. (2004). Screening rice varieties for allelopathic poten-tial against arrowhead (Sagittaria montevidensis), an aquatic weed infesting Australian Riverina rice crops. Crop Pasture Sci. 55:673-680.

Sharma, P.K. and De Datta, S.K. (1985). Effect of pud-dling on soil physical properties and processes. In “Soil Physics and Rice”, pp. 217-234. International Rice Research Institute, Los Banos, Philippines.

Sharma, P.K., Ladha, J.K. and Bhushan, L. (2003). Soil physical effects of puddling in rice-wheat cropping systems. In “Improving the productivity and sustaina-bility of rice-wheat systems: Issues and Impacts” (J. K. Ladha, J. E. Hill, J. M. Duxbury, R. K. Gupta, and R. J. Buresh, Eds.), pp. 97-113. ASA, CSSA, SSSA, Madison, WI, ASA Special Publication 65.

Singh, A., Kaur, R., Kang, J. S. and Singh, G. (2012). Weed dynamics in rice-wheat cropping system. Glob-al J. Bio., Agri. Health Sci. 1(1): 7-16.

Singh, A., Nandal, D. P. and Punia, S. S. (2017). Perfor-mance of sequential herbicides to control weeds in direct seeded rice. J. Applied Natural Sci. 9(3):1324-1328.

Singh, A.K. and Chinnusamy, V. (2006). Aerobic rice- Prospects for enhancing water productivity. Ind. Farm. 56(7): 58-61.

Singh, B. (1988). Effect of weed control methods on performance of rice varieties under upland rainfed conditions of Nagaland. Ind. J. Weed Sci. 20(2): 51-54.

Singh, G., Singh, R.G., Singh, O.P., Kumar, T., Mehta, R.K., Kumar, V. and Singh, R.P. (2005a). Effect of weed-management practices on direct-seeded rice under puddle lowlands. Ind. J. Agron. 50(2): 35-37.

Singh, G., Singh, V.P., Singh, Y., Singh, K.M., Mortimer, M., Johnson, D.E. and White, J. L. (2003). Efficacy of herbicides alone and in combinations in direct seeded rice. Biennial Conference ISWS, March 12-14, G.B. P.U.A.&T., Pantnagar. pp. 03

Singh, K., Kumar, V., Saharawat, Y. S., Gathala, M. and Ladha, J. K. (2013). Weedy rice: An emerging threat for direct seeded rice production systems in India. J. Rice Rese. 1:106.

Singh, R. G., Singh, S., Singh, V. and Gupta, R. K. (2010). Efficacy of azimsulfuron applied alone and tank mixed with metsulfuron+ chlorimuron (Almix) in dry direct seeded rice. Ind. J. Weed Sci. 42(3&4):168-172.

Singh, S., Bhushan, L., Ladha, J. K., Gupta, R. K., Rao, A. N., and Sivaprasad, B. (2006). Weed management in dry‐seeded rice (Oryza sativa) cultivated in the furrow‐irrigated raised‐bed planting system. Crop Prot. 25, 487–495.

Singh, S., Bhushan, L., Ladha, J.K., Gupta, R.K., Rao,

A.N. and Shivprasad, B. (2007). Evaluation of mulch-ing, Inter-cropping with Sesbania and herbicide use for weed management in dry-seeded rice (Oryza sati-va L.). Crop Prot. 26: 518-524.

Singh, S., Bhushan, L., Ladha, J.K., Gupta, R.K., Rao, A.N. and Shivprasad, B. (2008). Weed management in aerobic rice systems under varying establishment methods. Crop Prot. 27(3-5): 660-671.

Singh, S., Chhokar, R.S., Gopal, R., Ladha, J.K., Ku-mar, V. and Singh, M. (2009). Integrated weed man-agement : A key to success for direct-seeded rice in the Indo-Gangetic plains. In :”Integrated Crop and Resource Management in the Rice-Wheat System of South Asia” (J. K. Ladha, Y. Singh, O. Erenstein, and B. Hardy, Eds.), pp. 261-278. International Rice Re-search institute, Los Banos, Philippines.

Singh, S., Singh, G., Singh, V.P. and Singh, A.P. (2005b). Effect of establishment methods and weed management practices on weeds and rice in rice-wheat cropping system. Ind. J. Weed Sci. 37(1&2): 51-57.

Singh, V., Jat, M. L., Ganie, Z. A., Chauhan, B. S. and Gupta, R. K. (2016). Herbicide options for effective weed management in dry direct seeded rice under scented rice-wheat rotation of western Indo Gangetic Plains. Crop Prot. 81:168-176.

Singh, V.P., Singh, G., Singh, S.P., Kumar, A., Singh, Y., Johnson, D.E. and Mortimer, M. (2005c). Effect of rice wheat establishment methods and weed manage-ment in irrigated rice-wheat production system. In: Workshop on “Direct seeded rice in the rice-wheat system of the Indo-Gangetic Plains”, 1-2 feb. 2005, Pantnagar, Uttaranchal, India, pp. 12.

Singh, Y., Singh, G., Singh, V.P., Singh, R.K., Singh, P., Srivastava, R.S.I. and Saxena, A. (2002). Effect of different establishment methods on rice-wheat and the implication of weed management in Indo-Gangetic Plains. Proceedings of International Workshop on Herbicide resistance management and zero-tillage in rice-wheat system, Hisar, India, March 4-6, 2002. pp. 182 186.

Soo, L. K., Subinon, B. J. and Thong, O. S. (1989). Cul-tural practices and paddy planting in the TrusanSapi Paddy Project Proceeding In-house Seminar on Pad-dy, Department of Agriculture, Kuala Lumpur, Malay-sia.

Tabbal, D.P., Bouman, B.A.M., Bhuiyan, S.L., Sibayan, E.B. and Sattar, M.A. (2002). On-farm strategies for reducing water input in irrigated rice: Case studies in the Philippines. Agri. Water Manag. 56(2): 93-112.

Thakur, T.C. (2006). Rice engineering aspects. Ind. Far. 56(7): 53-57.

Talukder, A., Meisner, C., Baksh, M., Waddington, S. (2006). Wheat-maize-rice cropping on permanent raised beds in Bangladesh. In: Humphreys, E., Roth, C.H. (Eds.), Permanent Beds and Rice Residue Man-agement for Rice-wheat Systems in the Indo-Gangetic plains. ACIAR Workshop Proceedings No. 127, ACIAR, Canberra, Australia, pp. 124-132.

Upasani, R. R. and Barla, S. (2014). Weed control meth-ods in direct seeded rice under medium land condi-tion. J. Crop Weed. 10(2):445-450.

Walia, U.S., Bhullar, M.S., Shelly, N. and Walia, S.S. (2008). Control of complex weed flora of dry-seeded rice (Oryza sativa) with pre- and post-emergence herbicides. Ind. J. Weed Sci. 40, 161-164.

Walia, U.S., Walia, S.S., Amandeep, S.S. and Shelly, N.

Singh A. et al. / J. Appl. & Nat. Sci. 10 (2): 779 - 790 (2018)

790

(2012). Bioefficacy of pre-and post-emergence herbi-cides in direct-seeded rice in Central Punjab. Ind. J.Weed Sci. 44: 30 33.

Wells, B. R. and Faw, W. F. (1978). Short-statured rice response to seeding and N rates. Agron. J. 70:477-480.

Wentao, R., Mingjin, X., Jing, L., Chunjiang, B., Yuqiu, S. ahind Ruili, W. (2003). Experimental study on ef-fect of paper-mulching rice planting technology on saving water and controlling weeds. Transactions of the Chinese Society of Agricultural Engineering. 6:014.

Xuan, T. D., Tsuzuki, E., Terao, H., Matsuo, M., Khanh,

T. D., Murayama, S., Hong and N. H. (2003). Alfalfa, rice by-products and their incorporation for weed con-trol in rice. Weed Bio. Manag. 3:137-144.

Yadav, S., Gill, M. S. and Kukal, S. S. (2007). Perfor-mance of direct-seeded basmati rice in loamy sand in semi-arid subtropical India. Soil Till. Rese. 97:229–238.

Zhao, D., Atlin, G., Bastiaans, L. and Spiertz, J. (2006). Developing selection protocols for weed competitive-ness in aerobic rice. Field Crops Rese. 97: 272-285.

Singh A. et al. / J. Appl. & Nat. Sci. 10 (2): 779 - 790 (2018)